Strengthen The Yimen Sulfide Copper Minerals Bacterial Leaching Process

The composition of mineralogy of the copper-sulphide ore from Yimen mine was firstly studied in this thesis .On the base, the probability of bioleaching to the coppersulphide ore was studied. The bioleaching experiments by bacteria which were isolated from the acidic water of a mineral of Hunan province indicated that bioleaching was an efficient way to deal with the ore. The preliminary mechanism of bioleaching is discussed lastly.The ore sample from YiMen mine assays approximatelyCu 1.33%, TFe 25.46%, S 1.24%, A1203 9.10%, CaO 1.87%, MgO 3.13%, As 0.015%, Si02 36.70%, Ag2.49(g/t).The copper ore contains chalcopyrite 82.91% and chalcomiclite about 16.84%,it also contains a little covellite and malachite .In the iron mineral ,magnetite takes the primary place ,the next are hematite and pyrite ,in addition,it also contains a little limonite.Bacteria (Thiobacillus ferroxidans) isolated from the acidic water of a mineral of Hunan province in this study can oxide all sulfide minerals in the ore and improve the copper extraction effectively. They were enriched or grown first in acid ferrous sulfate medium (9K medium), then purified in solid medium containing agars. Thiobacillus ferroxidans not only can oxidize ferrous iron, but also can grow with energy derived from elemental sulfur and thiosulfate oxidation .The bioleaching experiments shown that bacterial activity, medium and the size of mine were the main effecting factors on bioleaching of Yimen copper7ore. Then we used the bacteria to do direct and strengthening leaching experiment to the sample. Through catalytic oxidation method, the copper leaching ratio may reach 51.586% by bioleaching for 180 days,it is only 40.638% in the experiment of bioleaching directly. The copper leaching ratio raises 10.947%.The preliminary mechanism of bioleaching is discussed lastly.In a word, bioleaching is an effective method to deal with Yimen sulfide copper ore.